qqmlvmemetaobject_p.h

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// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2016 BasysKom GmbH.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant
 
#ifndef QQMLVMEMETAOBJECT_P_H
#define QQMLVMEMETAOBJECT_P_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include "qqmldata_p.h"
#include <private/qbipointer_p.h>
#include <private/qqmlguard_p.h>
#include <private/qqmlguardedcontextdata_p.h>
#include <private/qqmlpropertyvalueinterceptor_p.h>
#include <private/qv4object_p.h>
#include <private/qv4value_p.h>
 
#include <QtCore/private/qobject_p.h>
 
#if QT_CONFIG(regularexpression)
#include <QtCore/qregularexpression.h>
#endif
 
#include <QtCore/qbitarray.h>
#include <QtCore/qdatetime.h>
#include <QtCore/qdebug.h>
#include <QtCore/qlist.h>
#include <QtCore/qmetaobject.h>
 
QT_BEGIN_NAMESPACE
 
class QQmlVMEMetaObject;
class QQmlVMEResolvedList
{
    Q_DISABLE_COPY_MOVE(QQmlVMEResolvedList)
 
public:
    QQmlVMEResolvedList(QQmlListProperty<QObject> *prop);
    ~QQmlVMEResolvedList();
 
    QQmlVMEMetaObject *metaObject() const { return m_metaObject; }
    QV4::Heap::Object *list() const { return m_list; }
    quintptr id() const { return m_id; }
 
    // if m_propertyAndMethodStorage of the object is gone,
    // the list is unusable
    bool isValid() const { return m_list; }
 
    void append(QObject *o) const;
    void replace(qsizetype i, QObject *o) const;
    QObject *at(qsizetype i) const;
 
    qsizetype size() const
    {
        Q_ASSERT(isValid());
        return m_list->arrayData->length();
    }
 
    void clear() const
    {
        Q_ASSERT(isValid());
 
        QV4::Scope scope(m_list->internalClass->engine);
        QV4::ScopedObject object(scope, m_list);
        m_list->arrayData->vtable()->truncate(object, 0);
    }
 
    void removeLast() const
    {
        Q_ASSERT(isValid());
 
        const uint length = m_list->arrayData->length();
        if (length == 0)
            return;
 
        QV4::Scope scope(m_list->internalClass->engine);
        QV4::ScopedObject object(scope, m_list);
        m_list->arrayData->vtable()->truncate(object, length - 1);
    }
 
    void activateSignal() const;
 
private:
    QQmlVMEMetaObject *m_metaObject = nullptr;
    QV4::Heap::Object *m_list = nullptr;
    quintptr m_id = 0;
};
 
class QQmlVMEVariantQObjectPtr : public QQmlGuard<QObject>
{
public:
    inline QQmlVMEVariantQObjectPtr();
 
    inline void setGuardedValue(QObject *obj, QQmlVMEMetaObject *target, int index);
 
    QQmlVMEMetaObject *m_target;
    int m_index;
 
private:
    static void objectDestroyedImpl(QQmlGuardImpl *guard);
};
 
 
class Q_QML_EXPORT QQmlInterceptorMetaObject : public QDynamicMetaObjectData
{
public:
    QQmlInterceptorMetaObject(QObject *obj, const QQmlPropertyCache::ConstPtr &cache);
    ~QQmlInterceptorMetaObject() override;
 
    void registerInterceptor(QQmlPropertyIndex index, QQmlPropertyValueInterceptor *interceptor);
 
    static QQmlInterceptorMetaObject *get(QObject *obj);
 
#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0)
    const QMetaObject *toDynamicMetaObject(QObject *o) const override;
#else
    QMetaObject *toDynamicMetaObject(QObject *o) override;
#endif
 
    // Used by auto-tests for inspection
    QQmlPropertyCache::ConstPtr propertyCache() const { return cache; }
 
    // Re-point this meta-object at an identically-shaped property cache. Used by the QML preview's
    // in-place patch to give a live instance the reloaded type's identity, so it keeps satisfying
    // is-a checks against consumers whose type references were redirected to the new unit. The
    // lazily-built dynamic meta-object is dropped so it is rebuilt from the new cache on next use.
    void setPropertyCache(const QQmlPropertyCache::ConstPtr &newCache)
    {
        cache = newCache;
        metaObject = QTaggedPointer<const QMetaObject, MetaObjectValidity>();
    }
 
    bool intercepts(QQmlPropertyIndex propertyIndex) const
    {
        for (auto it = interceptors; it; it = it->m_next) {
            if (it->m_propertyIndex == propertyIndex)
                return true;
        }
        if (auto parentInterceptor = ((parent.isT1() && parent.flag()) ? static_cast<QQmlInterceptorMetaObject *>(parent.asT1()) : nullptr))
            return parentInterceptor->intercepts(propertyIndex);
        return false;
    }
 
    void invalidate() { metaObject.setTag(MetaObjectInvalid); }
 
    // only used for Bindable so far; Write instead passes a flag via the metacall
    enum InterceptionBehavior { Intercept, SkipInterception };
    static void setInterceptionMode(QObject *object, InterceptionBehavior behavior);
 
    QTaggedPointer<QObject> object = nullptr;
    QQmlPropertyCache::ConstPtr cache;
 
protected:
    int metaCall(QObject *o, QMetaObject::Call c, int id, void **a) override;
    bool intercept(QMetaObject::Call c, int id, void **a)
    {
        if (!interceptors)
            return false;
 
        switch (c) {
        case QMetaObject::WriteProperty:
            if (*reinterpret_cast<int*>(a[3]) & QQmlPropertyData::BypassInterceptor)
                return false;
            break;
        case QMetaObject::BindableProperty:
            if (object.tag() == SkipInterception) {
                return false;
            }
            break;
        default:
            return false;
        }
 
        return doIntercept(c, id, a);
    }
 
    QBiPointer<QDynamicMetaObjectData, const QMetaObject> parent;
 
    enum MetaObjectValidity { MetaObjectValid, MetaObjectInvalid };
    QTaggedPointer<const QMetaObject, MetaObjectValidity> metaObject;
 
private:
    bool doIntercept(QMetaObject::Call c, int id, void **a);
    QQmlPropertyValueInterceptor *interceptors = nullptr;
};
 
inline QQmlInterceptorMetaObject *QQmlInterceptorMetaObject::get(QObject *obj)
{
    if (obj) {
        if (QQmlData *data = QQmlData::get(obj)) {
            if (data->hasInterceptorMetaObject)
                return static_cast<QQmlInterceptorMetaObject *>(QObjectPrivate::get(obj)->metaObject);
        }
    }
 
    return nullptr;
}
 
inline void QQmlInterceptorMetaObject::setInterceptionMode(
        QObject *object, QQmlInterceptorMetaObject::InterceptionBehavior behavior)
{
    QQmlInterceptorMetaObject *interceptorMetaObject = get(object);
    while (interceptorMetaObject) {
        interceptorMetaObject->object.setTag(behavior);
        auto parent = interceptorMetaObject->parent;
        interceptorMetaObject = ((parent.isT1() && parent.flag()) ? static_cast<QQmlInterceptorMetaObject *>(parent.asT1()) : nullptr);
    }
}
 
class QQmlVMEMetaObjectEndpoint;
class Q_QML_EXPORT QQmlVMEMetaObject : public QQmlInterceptorMetaObject
{
public:
    QQmlVMEMetaObject(
            QV4::ExecutionEngine *engine, QObject *obj, const QQmlPropertyCache::ConstPtr &cache,
            const QQmlRefPointer<QV4::ExecutableCompilationUnit> &qmlCompilationUnit,
            int qmlObjectId);
    ~QQmlVMEMetaObject() override;
 
    bool aliasTarget(int index, QObject **target, int *coreIndex, int *valueTypeIndex) const;
    QV4::ReturnedValue vmeMethod(int index) const;
    void setVmeMethod(int index, const QV4::Value &function);
    QV4::ReturnedValue vmeProperty(int index) const;
    void setVMEProperty(int index, const QV4::Value &v);
 
    void connectAliasSignal(int index, bool indexInSignalRange);
 
    static inline QQmlVMEMetaObject *get(QObject *o);
    static QQmlVMEMetaObject *getForProperty(QObject *o, int coreIndex);
    static QQmlVMEMetaObject *getForMethod(QObject *o, int coreIndex);
    static QQmlVMEMetaObject *getForSignal(QObject *o, int coreIndex);
 
    static void list_append(QQmlListProperty<QObject> *prop, QObject *o);
    static void list_clear(QQmlListProperty<QObject> *prop);
    static void list_append_nosignal(QQmlListProperty<QObject> *prop, QObject *o);
    static void list_clear_nosignal(QQmlListProperty<QObject> *prop);
 
    inline int propOffset() const;
    inline int propCount() const;
    inline int aliasOffset() const;
    inline int aliasCount() const;
    inline int signalOffset() const;
    inline int signalCount() const;
    inline int methodOffset() const;
    inline int methodCount() const;
 
    QV4::MemberData *propertyAndMethodStorageAsMemberData() const;
 
    int readPropertyAsInt(int id) const;
    bool readPropertyAsBool(int id) const;
    double readPropertyAsDouble(int id) const;
    QString readPropertyAsString(int id) const;
    QSizeF readPropertyAsSizeF(int id) const;
    QPointF readPropertyAsPointF(int id) const;
    QUrl readPropertyAsUrl(int id) const;
    QDate readPropertyAsDate(int id) const;
    QTime readPropertyAsTime(int id) const;
    QDateTime readPropertyAsDateTime(int id) const;
 
#if QT_CONFIG(regularexpression)
    QRegularExpression readPropertyAsRegularExpression(int id) const;
#endif
 
    QRectF readPropertyAsRectF(int id) const;
    QObject *readPropertyAsQObject(int id) const;
    void initPropertyAsList(int id) const;
 
    void writeProperty(int id, int v);
    void writeProperty(int id, bool v);
    void writeProperty(int id, double v);
    void writeProperty(int id, const QString& v);
 
    template<typename VariantCompatible>
    void writeProperty(int id, const VariantCompatible &v)
    {
        QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
        if (md) {
            QV4::Scope scope(m_engine);
            QV4::Scoped<QV4::MemberData>(scope, md)->set(
                        m_engine, id, m_engine->newVariantObject(
                            QMetaType::fromType<VariantCompatible>(), &v));
        }
    }
 
    void writeProperty(int id, QObject *v);
 
    void ensureQObjectWrapper();
 
    void mark(QV4::MarkStack *markStack);
 
    void connectAlias(const QV4::CompiledData::Object *compiledObject, int aliasId);
 
    QV4::ReturnedValue method(int) const;
 
    QV4::ReturnedValue readVarProperty(int) const;
    void writeVarProperty(int, const QV4::Value &);
    QVariant readPropertyAsVariant(int) const;
 
    inline QQmlVMEMetaObject *parentVMEMetaObject() const;
    inline void setParentVMEMetaObject(QQmlVMEMetaObject *newParent);
 
    void activate(QObject *, int, void **);
 
    QQmlVMEVariantQObjectPtr *getQObjectGuardForProperty(int) const;
 
    QQmlRefPointer<QQmlContextData> contextData() const { return m_ctxt.contextData(); }
    QV4::ExecutionEngine *engine() const { return m_engine; }
    QQmlRefPointer<QV4::ExecutableCompilationUnit> compilationUnit() const
    {
        return m_compilationUnit;
    }
 
    void setCompilationUnit(const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit)
    {
        m_compilationUnit = compilationUnit;
    }
 
    int qmlObjectId() const { return m_qmlObjectId; }
 
protected:
    int metaCall(QObject *o, QMetaObject::Call _c, int _id, void **_a) override;
    bool getListProperty(int id, QQmlListProperty<QObject> *target);
 
private:
    friend class QQmlVMEMetaObjectEndpoint;
    friend class QQmlVMEResolvedList;
    friend class QQmlVMEVariantQObjectPtr;
 
    const QV4::CompiledData::Object *findCompiledObject() const {
        // If the executable CU has been stripped of its engine, it has an empty base CU
        if (!m_compilationUnit || !m_compilationUnit->engine)
            return nullptr;
 
        Q_ASSERT(m_qmlObjectId >= 0 && m_qmlObjectId < m_compilationUnit->objectCount());
        return m_compilationUnit->objectAt(m_qmlObjectId);
    }
 
    void writeKnownVarProperty(int id, const QVariant &value);
 
    QV4::ExecutionEngine *m_engine;
    QQmlGuardedContextData m_ctxt;
 
    QQmlVMEMetaObjectEndpoint *m_aliasEndpoints;
    QV4::WeakValue m_propertyAndMethodStorage;
 
    QList<QQmlVMEVariantQObjectPtr *> m_varObjectGuards;
 
    // keep a reference to the compilation unit in order to still
    // do property access when the context has been invalidated.
    QQmlRefPointer<QV4::ExecutableCompilationUnit> m_compilationUnit;
    int m_qmlObjectId = -1;
    int m_numAliases = 0;
};
 
QQmlVMEMetaObject *QQmlVMEMetaObject::get(QObject *obj)
{
    if (obj) {
        if (QQmlData *data = QQmlData::get(obj)) {
            if (data->hasVMEMetaObject)
                return static_cast<QQmlVMEMetaObject *>(QObjectPrivate::get(obj)->metaObject);
        }
    }
 
    return nullptr;
}
 
int QQmlVMEMetaObject::propOffset() const
{
    // Regular properties are before aliases
    return cache->propertyOffset();
}
 
int QQmlVMEMetaObject::propCount() const
{
    // Properties excluding aliases
    return cache->ownPropertyCount() - m_numAliases;
}
 
int QQmlVMEMetaObject::aliasOffset() const
{
    // Aliases are after regular properties
    return propOffset() + propCount();
}
 
int QQmlVMEMetaObject::aliasCount() const
{
    // We need to cache this since we don't want to count over and over.
    return m_numAliases;
}
 
int QQmlVMEMetaObject::signalOffset() const
{
    // Signals are before regular methods
    return cache->methodOffset();
}
 
int QQmlVMEMetaObject::signalCount() const
{
    // Signals including signals for properties and aliases
    return cache->ownSignalCount();
}
 
int QQmlVMEMetaObject::methodOffset() const
{
    // Regular methods are after signals
    return signalOffset() + signalCount();
}
 
int QQmlVMEMetaObject::methodCount() const
{
    // Methods excluding signals
    return cache->ownMethodCount() - signalCount();
}
 
QQmlVMEMetaObject *QQmlVMEMetaObject::parentVMEMetaObject() const
{
    if (parent.isT1() && parent.flag())
        return static_cast<QQmlVMEMetaObject *>(parent.asT1());
 
    return nullptr;
}
 
inline void QQmlVMEMetaObject::setParentVMEMetaObject(QQmlVMEMetaObject *newParent)
{
    parent = newParent;
    parent.setFlag();
}
 
QT_END_NAMESPACE
 
#endif // QQMLVMEMETAOBJECT_P_H